Alum

The alum industry operated in this area for over 250 years from about 1600. Alum was used as a mordant, or fixing agent, for holding natural dyes to fabrics. Alum is a group of double salts that contain aluminium sulphate in combination with a second sulphate (either potassium or ammonium). The Jurassic Upper Lias shales in North East England contain a vital ingredient in the manufacture of alum - aluminium sulphate. The nearest extraction and processing plant to Bilsdale is at Carlton Bank where the shale outcrops near the top of the north facing scarp of the moors. The complex is illustrated below. The process generated large quantities of reddish coloured spoil which disfigured the landscape, see photograph. In 1995 the North York Moors National Park Authority commissioned a major regeneration project to reclaim the area. During this project the remains of the alum workings were briefly uncovered and recorded.

More information about alum production at Carlton Bank from Oxford Archaeology.

The specific operations at this site require further research. Additional contributions to this brief summary would be welcome

the Bilsdale Local History Group visited the site and took some photographs in April 1998 when the remains of the alum works were visible